Technetium (Tc) - Element 43 | Properties & Electron Configuration
What is Technetium?
Technetium (Tc) is element 43, a transition metal in period 5, group 7. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁵ 5s².
| Atomic Number | 43 |
| Symbol | Tc |
| Atomic Mass | 98 u |
| Category | Transition Metal |
| Period | 5 |
| Group | 7 |
| Block | d |
| Electron Configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁵ 5s² |
| Short Config | [Kr] 4d⁵ 5s² |
| Electronegativity | 1.9 |
| Atomic Radius | 136 pm |
| Ionization Energy | 702 kJ/mol |
| Electron Affinity | 53 kJ/mol |
| Phase (STP) | Solid |
Electron Configuration
The full electron configuration of Technetium is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁵ 5s². In noble gas shorthand, this is written as [Kr] 4d⁵ 5s².
Technetium is a d-block element in group 7, period 5.
Periodic Trends
Electronegativity: Technetium has a Pauling electronegativity of 1.9. Within group 7, electronegativity generally decreases down the group.
Atomic Radius: 136 pm. Across period 5, atomic radius generally decreases left to right as nuclear charge increases.
Ionization Energy: 702 kJ/mol. Ionization energy generally increases across a period and decreases down a group.
View all 118 elements with trend overlays for electronegativity, atomic radius, ionization energy, and electron affinity.
Explore Technetium on the Interactive Periodic TableRelated Topics
Manganese (Mn)
Properties of Manganese - same group as Technetium
Rhenium (Re)
Properties of Rhenium - same group as Technetium
Bohrium (Bh)
Properties of Bohrium - same group as Technetium
Rubidium (Rb)
Properties of Rubidium - same period as Technetium
Strontium (Sr)
Properties of Strontium - same period as Technetium
Yttrium (Y)
Properties of Yttrium - same period as Technetium